def get_single_oid(snmp_config,
oid,
check_plugin_name=None,
do_snmp_scan=True):
# type: (SNMPHostConfig, str, Optional[str], bool) -> Optional[DecodedString]
# The OID can end with ".*". In that case we do a snmpgetnext and try to
# find an OID with the prefix in question. The *cache* is working including
# the X, however.
if oid[0] != '.':
if cmk.utils.debug.enabled():
raise MKGeneralException(
"OID definition '%s' does not begin with a '.'" % oid)
oid = '.' + oid
# TODO: Use generic cache mechanism
if snmp_cache.is_in_single_oid_cache(oid):
console.vverbose(" Using cached OID %s: " % oid)
cached_value = snmp_cache.get_oid_from_single_oid_cache(oid)
console.vverbose("%s%s%r%s\n" %
(tty.bold, tty.green, cached_value, tty.normal))
return cached_value
# get_single_oid() can only return a single value. When SNMPv3 is used with multiple
# SNMP contexts, all contextes will be queried until the first answer is received.
if check_plugin_name is not None and snmp_config.is_snmpv3_host:
snmp_contexts = _snmpv3_contexts_of(snmp_config, check_plugin_name)
else:
snmp_contexts = [None]
console.vverbose(" Getting OID %s: " % oid)
for context_name in snmp_contexts:
try:
value = SNMPBackendFactory.get(snmp_config,
use_cache=_enforce_stored_walks,
oid=oid,
context_name=context_name)
if value is not None:
break # Use first received answer in case of multiple contextes
except Exception:
if cmk.utils.debug.enabled():
raise
value = None
if value is not None:
console.vverbose("%s%s%r%s\n" %
(tty.bold, tty.green, value, tty.normal))
else:
console.vverbose("failed.\n")
if value is not None:
decoded_value = convert_to_unicode(
value, encoding=snmp_config.character_encoding
) # type: Optional[DecodedString]
else:
decoded_value = value
snmp_cache.set_single_oid_cache(oid, decoded_value)
return decoded_value
def _snmp_scan(host_config,
on_error="ignore",
for_inv=False,
do_snmp_scan=True,
for_mgmt_board=False):
# type: (SNMPHostConfig, str, bool, bool, bool) -> Set[CheckPluginName]
import cmk.base.inventory_plugins as inventory_plugins # pylint: disable=import-outside-toplevel
# Make hostname globally available for scan functions.
# This is rarely used, but e.g. the scan for if/if64 needs
# this to evaluate if_disabled_if64_checks.
check_api_utils.set_hostname(host_config.hostname)
snmp_cache.initialize_single_oid_cache(host_config)
console.vverbose(" SNMP scan:\n")
if not config.get_config_cache().in_binary_hostlist(host_config.hostname,
config.snmp_without_sys_descr):
for oid, name in [(".1.3.6.1.2.1.1.1.0", "system description"),
(".1.3.6.1.2.1.1.2.0", "system object")]:
value = snmp.get_single_oid(host_config, oid, do_snmp_scan=do_snmp_scan)
if value is None:
raise MKSNMPError(
"Cannot fetch %s OID %s. This might be OK for some bogus devices. "
"In that case please configure the ruleset \"Hosts without system "
"description OID\" to tell Check_MK not to fetch the system "
"description and system object OIDs." % (name, oid))
else:
# Fake OID values to prevent issues with a lot of scan functions
console.vverbose(" Skipping system description OID "
"(Set .1.3.6.1.2.1.1.1.0 and .1.3.6.1.2.1.1.2.0 to \"\")\n")
snmp_cache.set_single_oid_cache(".1.3.6.1.2.1.1.1.0", "")
snmp_cache.set_single_oid_cache(".1.3.6.1.2.1.1.2.0", "")
if for_inv:
these_plugin_names = [
name for name in inventory_plugins.inv_info if inventory_plugins.is_snmp_plugin(name)
]
else:
# TODO (mo): stop converting to string!
these_plugin_names = [str(n) for n in config.registered_snmp_sections]
found_plugins = set() # type: Set[CheckPluginName]
for check_plugin_name in these_plugin_names:
if config.service_ignored(host_config.hostname, check_plugin_name, None):
continue
detection_spec = _get_detection_spec_from_plugin_name(check_plugin_name,
inventory_plugins.inv_info)
if detection_spec is None:
console.warning(" SNMP check %s: Could not detect specifications for plugin" %
check_plugin_name)
continue
try:
def oid_function(oid, default_value=None, cp_name=check_plugin_name):
# type: (OID, Optional[DecodedString], Optional[CheckPluginName]) -> Optional[DecodedString]
value = snmp.get_single_oid(host_config, oid, cp_name, do_snmp_scan=do_snmp_scan)
return default_value if value is None else value
if callable(detection_spec):
result = detection_spec(oid_function)
else:
result = _evaluate_snmp_detection(oid_function, detection_spec)
if result is not None and not isinstance(result, (str, bool)):
if on_error == "warn":
console.warning(" SNMP scan function of %s returns invalid type %s." %
(check_plugin_name, type(result)))
elif on_error == "raise":
raise MKGeneralException("SNMP Scan aborted.")
elif result:
found_plugins.add(check_plugin_name)
except MKGeneralException:
# some error messages which we explicitly want to show to the user
# should be raised through this
raise
except Exception:
if on_error == "warn":
console.warning(" Exception in SNMP scan function of %s" % check_plugin_name)
elif on_error == "raise":
raise
_output_snmp_check_plugins("SNMP scan found", found_plugins)
filtered = config.filter_by_management_board(
host_config.hostname,
found_plugins,
for_mgmt_board,
for_discovery=True,
for_inventory=for_inv,
)
_output_snmp_check_plugins("SNMP filtered check plugin names", filtered)
snmp_cache.write_single_oid_cache(host_config)
return filtered
def _snmp_scan(host_config,
on_error="ignore",
for_inv=False,
do_snmp_scan=True,
for_mgmt_board=False):
# type: (SNMPHostConfig, str, bool, bool, bool) -> Set[CheckPluginName]
import cmk.base.inventory_plugins as inventory_plugins # pylint: disable=import-outside-toplevel
# Make hostname globally available for scan functions.
# This is rarely used, but e.g. the scan for if/if64 needs
# this to evaluate if_disabled_if64_checks.
check_api_utils.set_hostname(host_config.hostname)
snmp_cache.initialize_single_oid_cache(host_config)
console.vverbose(" SNMP scan:\n")
if not config.get_config_cache().in_binary_hostlist(
host_config.hostname, config.snmp_without_sys_descr):
for oid, name in [(".1.3.6.1.2.1.1.1.0", "system description"),
(".1.3.6.1.2.1.1.2.0", "system object")]:
value = snmp.get_single_oid(host_config,
oid,
do_snmp_scan=do_snmp_scan)
if value is None:
raise MKSNMPError(
"Cannot fetch %s OID %s. This might be OK for some bogus devices. "
"In that case please configure the ruleset \"Hosts without system "
"description OID\" to tell Check_MK not to fetch the system "
"description and system object OIDs." % (name, oid))
else:
# Fake OID values to prevent issues with a lot of scan functions
console.vverbose(
" Skipping system description OID "
"(Set .1.3.6.1.2.1.1.1.0 and .1.3.6.1.2.1.1.2.0 to \"\")\n")
snmp_cache.set_single_oid_cache(".1.3.6.1.2.1.1.1.0", "")
snmp_cache.set_single_oid_cache(".1.3.6.1.2.1.1.2.0", "")
# TODO (mo): Assumption here is that inventory plugins are significantly fewer
# than check plugins. We should pass an explicit list along, instead
# of this flag. That way we would also get rid of the import above.
if for_inv:
section_names = [PluginName(n) for n in inventory_plugins.inv_info]
these_sections = [
config.registered_snmp_sections[section_name]
for section_name in section_names
if section_name in config.registered_snmp_sections
]
else:
these_sections = list(config.registered_snmp_sections.values())
found_plugins = set() # type: Set[CheckPluginName]
for section_plugin in these_sections:
try:
if _evaluate_snmp_detection(
section_plugin.detect_spec,
host_config,
str(section_plugin.name),
do_snmp_scan,
):
found_plugins.add(str(section_plugin.name))
except MKGeneralException:
# some error messages which we explicitly want to show to the user
# should be raised through this
raise
except Exception:
if on_error == "warn":
console.warning(" Exception in SNMP scan function of %s" %
section_plugin.name)
elif on_error == "raise":
raise
_output_snmp_check_plugins("SNMP scan found", found_plugins)
filtered = config.filter_by_management_board(
host_config.hostname,
found_plugins,
for_mgmt_board,
for_discovery=True,
for_inventory=for_inv,
)
_output_snmp_check_plugins("SNMP filtered check plugin names", filtered)
snmp_cache.write_single_oid_cache(host_config)
return filtered
